A new review by two intelligence agencies has backed up an earlier conclusion that at least two emails on Hillary Clinton's personal server contained "top secret" information.

The review by the Central Intelligence Agency and the National Geospatial-Intelligence Agency went back to the original source documents, and follows the finding last month by the intelligence community inspector general that emails on the former secretary of state's system contained information at the highest classification level. This included intelligence on special programs about North Korea's nuclear weapons.

Fox News is told the CIA and NGA did the review because their intelligence was at issue. Only the intelligence agency that gets the information in the first place has the authority to determine its classification.

In both emails, the State Department did not generate the intelligence, and therefore did not have classification authority. The inspector general's August report simply transmitted the classification findings of the CIA and NGA.

In a statement, Andrea Williams, a spokeswoman for the intelligence community inspector general, said "the overall classification of those two emails remains unchanged. Both emails were classified when they were created and remain classified now."

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The conclusion further undercuts the Clinton campaign's claim that the classification issue amounts to a dispute among agencies.

She said Aug. 18 in Las Vegas, "What you're seeing now is a disagreement between agencies saying, 'you know what, they should have,' and the other saying, 'no, they shouldn't.' That has nothing to do with me."

Campaign spokesman Nick Merrill told the Times, ''Our hope remains that these releases continue without being hampered by bureaucratic infighting among the intelligence community, and that the releases continue to be as inclusive and transparent as possible."

Only the Clinton campaign and State Department are challenging the "top secret" classification.

The latest review, where original source material was reviewed, shows there is no daylight between Intelligence Community Inspector General I. Charles McCullough III and the agencies that owned the highly classified intelligence found on Clinton's server.

And it could cause problems for the Democratic presidential front-runner as she tries to shake off and downplay questions about the private system.

She told the Associated Press in an interview that "what I did was allowed" and reiterated that she did not "send or receive" information marked classified at the time.

And she again boiled down the debate to a dispute among agencies.

"There is always a debate among different agencies about what something should be retroactively (marked classified)," Clinton told the AP. "But at the time, there were none. So I'm going to keep answering the questions and providing the facts so that people can understand better what happened."

Clinton gave her server and thumb drive to the FBI a month ago.

Catherine Herridge is an award-winning Chief Intelligence correspondent for FOX News Channel (FNC) based in Washington, D.C. She covers intelligence, the Justice Department and the Department of Homeland Security. Herridge joined FNC in 1996 as a London-based correspondent.